Production of 1, 3-diols



Patented Sept. 7, 1948 PRODUCTION OF 1,3-DIOLS Louis A. Mikeska andErving Arundale, Westiield, N. J., assignors to Standard Oil DevelopmentCompany, a corporation of Delaware No Drawing. Application May 27, 1944,Serial No. 537,739

This application is a continuation-in-part of application Serial No.291,101, filed August 19, 1939, now abandoned.

The present invention relates to a method for the production of1,3-dihydric alcohols (glycols) or their derivatives from low molecularweight aliphatic oiefins or olefins substituted by an aromatic nucleus,hydroaromatic olefins. dienes, substituted unsaturated compounds, ormixtures of these with saturated hydrocarbons by condensing theunsaturated compounds with aldehydes in the presence of dilute ternaryor quaternary mineral acids, or other. acid-acting compounds ascatalysts. Ternary and quaternary mineral acids are those mineral acidswhose molecules consist of three and four different types of atoms,respec-1 tively. Other unsaturated compounda'such as unsaturated ethersand halides, may also be used. The simplest compound made according tothis method is 1,3-propylene glycol or 1,3-propanediol which is formedin the reaction of ethylene with formaldehyde.

8 Claims. (Cl. 260-635) 1,3-pr0panediol has been found among thebyproducts of the fermentation of glycerol and glucose. 1,3-butanediolhas been prepared by the reduction of acetaldol and by the action ofmagnesium amalgam on aqueous acetaldehyde. Higher members of the seriescan be prepared by similar reactions from the corresponding aldehydesand aldols, but these synthetic methods cannot be considered to be on acommercial basis. It has also been proposed to produce 1,3-butanediol byreacting propylene with formaldehydehydrate at approximately 70 C.,under pressure, and in the presence of hydrogen chloride, as in U. S.Patent 2,143,370. In this process the yields of 1,3-butanediol are lowdue to the formation of beta-chlorobutanol and other by-products. It istherefore apparent that a new method for producing such compounds inhigher yields is desirable.

According to the present invention. olefins and aldehydes are condensedin the presence of dilute aqueous solution of ternary or quaternarymineral acids, such as sulfuric, sulfur'ous, phosphoric, phosphorous,fluorsulfonic, fiuo'silicic, dihydroxy fiuoboric, and hydrofluoboricacids or acid-acting metallic salts of polybasic mineral acids, such asNaHSO4, NaHzPOa ZnSO4, Fez (SO03, A I2(SO4)3 and the like, of between.01 and 5 concentration, at elevated temperatures and pressures, thepressure used being at least equal to the vapor pressure of the reactionmixture at the operating temperature. The olefin should be present inexcess of the amount required to give a 1/1 olefinaldehyde mole ratio.Dilute acids, or other acidacting catalysts, of between 0.01 and 5%concentration are used in order to minimize the formation of cyclicdiethers. The aldehyde may be allphatic, such as formaldehyde(formalin), acetaldehyde, propionaldehyde, aromatic, such asbenzaldehyde, araliphatic, or any compound, such as paraldehyde, ortrioxymethylene or other polymers of formaldehyde, which will decomposeto yield an aldehyde, may be used. The reaction may be brought about bycontacting an aldehyde with an excess of olefin at elevated temperaturesin the presence of a dilute mineral acid-acting catalyst in a closedcontainer capable of withstanding high pressures and maintaining contactbetween the reactants by agitation until the reaction is completed, asindicated by the constancy of the pressure. When the materials are firstheated, the pressure increases untilthe desired operating conditions areattained, after which the pressure gradually diminishes as the reactionproceeds.

It has been further found that there is a deflnite relationship betweenthe ratio of-water to aldehyde present in the reaction mixture and theamount of diol obtained as a reaction product. This ratio has beendetermined as being about three parts by weight of water as a minimum toone part by weight of aldehyde. Any further reduction in the amount ofwater below this minimum results in a sharp reduction in the quantity ofdiol obtained from the reaction. Larger amounts of water in the relationto the aldehyde present in the reaction may be used and an increasinglylarger percentage yield of diol is obtained thereby, such increase inwater content present in the reaction mixturebeing limited or controlledonly by the economics of mechanical handling and distribution. It hasbeen found that as much as 30 parts of water per part of aldehyde can bereadily handled, although it is preferred to use about 20 parts byweight of water to 1 part by weight of aldehyde.

The temperature necessary for the reaction between an olefin and analdehyde to form dihydric alcohols differs with the different oleflnsaccording to the reactivity of the olefin. The lower olefins are lessreactive and require higher temperatures. With propylene, for example,temperatures of C. give good results, with ethylene, temperatures aboveabout C. are desirable, and with tertiary oleflns, such as isobutylene,temperatures as low as 50 C. are quite ture is neutralized and filtered,and the water and other constituents boiling below the boiling point ofthe dihydric alcohol are removed from th filtrate by distillation. Thisaqueous distillate may -be recycled to the olefin-aldehyde condensationreactor. since it contains diethers and other products; the presence ofsuch products in the reactor tends to repress the formation of similarproducts in the next. condensation reaction. The residue from the firstdistillation step is vacuum-distilled to yield the pure 1,3 dihydricalcohol. Small amounts of cyclic diethers, saturated aliphatic alcohols,polymers of the glycols, hydrocarbon polmers and diolefins are formed asby-products in these reactions. As the concentration of the acid-actingcatalyst is increased, the saturated alcohol yields decrease and thecyclic diether yields increase. The method of this invention may beoperated as a batch or continuous process, and as a liquidor vaporphaseprocess.

The products are generally liquids boiling above 200 C. and having aspecific gravity greater than 1.0. They are useful as solvents, freezingpoint depressants, and intermediates in the production of syntheticresins, They may also be dehydrated to dienes or nitrated for theproduction of Diesel fuel ignition promoters.

The following examples are given for the purpose of illustrating theinvention:

Example 1 150 parts by weight of propylene and 81 parts by weight oftrioxymethylene (paraformaldehyde), together with 162 parts by weight of3% sulfuric acid equivalent to 1.95 parts of water per part offormaldehyde on a weight basis, were placed in a one-liter copper-linedbomb capable of withstanding 2000 lbs/sq. in. gauge pressure andagitated therein. The bomb was heated to 142 C. and was maintained atthis temperature for 17 hours. The pressure rose as the temperatureincreased until it was about 940 lbs/sq. in. gauge at 142 C.; thepressure gradually decreased as the reaction proceeded, although thetemperature remained substantially constant. The bomb and its contentswere cooled at the end of the reaction period, and the excess olefin wasbled oil. The excess olefin amounted to 68 parts by weight and could berecycled if desired. The contents of the bomb, 325 parts by weight, wereneutralized with sodium carbonate and filtered, and the filtrate wasdistilled under a fractionating column. After removal of the water andlow-boiling by-products by distillation at 100 C., the residue wasvacuum distilled under 2 mm. pressure; 125 parts by weight of pure 1,3-butanediol (boiling point. 204 C. at 760 mm.) were obtained in thedistillate. This is equivalent to a 50% yield of dihydric alcohol basedupon the aldehyde charged. By using a larger proportion of dilute acidbased upon the aldehyde charged, a higher yield of dihydric alcohol maybe obtained.

Example 2 646 parts of 3% sulfuric acid equivalent to 20:8 parts ofwater per part of fonnaldehyde, 30 parts of trioxymethylene, and 60parts of propylene 4 (all parts by weight) were contacted in acopperlined bomb at 135 C. for 17 hours. The glycol was isolated as inExample 1. 63 parts of 1.3- butanediol, equivalent to a 70% yield basedupon the aldehyde charged, were obtained in this reaction.

Example 3 250 parts of 3% sulfuric acid equivalent to 3 parts of Waterper part of formaldehyde, 81 parts of trioxymethylene and 150 parts ofpropylene (all parts by weight) were contacted in a copperlined bomb at135 C. for 17 hours. The glycol was isolated as in Example 1. 133.6parts of 1,3 butanediol, equivalent to a 55% yield based upon thealdehyde charged, were obtained in this reaction.

We claim:

1. A method for producing 1,3-dio1s which comprises reacting an olefinwith an aldehyde at elevated temperatures and pressures in the presenceof sulfuric acid of from .01 to 5% concentration, the weight of thewater present in said sulfuric acid being at least 3 times the weight ofthe aldehyde charged.

2. The process of producing 1,3-diols which comprises reacting an olefinwith, formaldehyde at elevated temperatures and pressures in thepresence of sulfuric acid of from .01 to 5% concentration, the weight ofthe water present in said sulfuric acid being at least 3 times theweight of the formaldehyde charged.

3. The process of producing 1,3-diols which comprises reacting a primaryolefin with formaldehyde at a temperature of at least 150 0. and at apressure at least equal to the vapor pressure of the reaction mixture inthe presence of sulfuric acid of from .01 to 5% concentration, theweight of the water present in said sulfuric acid being at least 3timesthe weight of the formaldehyde charged.

4. The process of producing 1,3-diols which comprises reacting asecondary olefin with formaldehyde at a temperature of at least 135 C.and at a pressure at least equal to the vapor pressure of the reactionmixture in the presence of sulfuric acid of from .01 to 5%concentration, the weight of the water present in said sulfuric acidbeing at least 3 times the weight of the formaldehyde charged.

5. The process of producing1,3-diols which comprises reacting a tertiaryolefin with formaldehyde at a temperature of at least 50 C. and. at apressure at least equal to the vapor pressure of the reaction mixture inthe presence of sulfuric acid of from .01 to 5% concentration. theweight of the water present in said sulfuric acid being at least 3 timesthe weight of the formaldehyde charged.

6. The process of producing 1,3-butanediol which consists in reactingpropylene with formaldehyde at temperatures above C. and at.

elevated pressures in the presence of .01 to 5% sulfuric acid, theweight of the water present in said sulfuric acid being from 3 to 30times the weight of the formaldehyde charged, neutralizing the reactionproduct, and recovering the dihydric alcohol from the neutralizedmixture.

'7. The process of making 1,3-butanediol which consists in reactingpropylene with formaldehyde at temperatures above 100 C. and at apressure at least equal to the vapor pressure of the reaction mixture inthe presence of 3% sulfuric acid, the weight of the water present insaid sulfuric acid being about 20 times the weight of the 5 formaldehydecharged, removing the unreacted olefin, neutralizing the reactionmixture, filtering, removing the water and other low boilingconstituents from the filtrate by distillation under refiux conditions,and then vacuum distilling the residue from the first distillation stepto recover the pure dihydrlc alcohol.

8. The process of making 3-methyl-1,3-butanediol which consists inreacting isobutylene with formaldehyde at a temperature above 50 C. andat a pressure at least equal to the vapor pressure of the reactionmixture in the presence of 1% sulfuric acid, the weight of the waterpresent in said sulfuric acid being about 20 times the weight of theformaldehyde charged, removing the unreacted olefin, neutralizing thereaction mixture, filtering, removing the water and other low boilingconstituents by distillation in a Iractionating column, and then vacuumdistilling the residue to recover the pure dihydric alcohol.

LOUIS A. MIKESKA. E'RVING ARUNDALE.

REFERENCES CITED The following references are of record in the file ofthis patent:

OTHER REFERENCES Prins, K. Akad, v. Wetenschapen, Proceedings Sec.Science," vol. 22, pages 51-6 (1919).

Ellis, "Chemistry of Petroleum Derivatives," vol. 11, pages 623-5.

